如何在ActiveDirectory和.NET 3.5中确定用户所属的所有组(包括嵌套组)

using System;
using System.DirectoryServices.AccountManagement;

public static List<GroupPrincipal> GetUserGroups(string userName)
{
    using (var context = new PrincipalContext(ContextType.Domain))
    {
        using (var user = UserPrincipal.FindByIdentity(context, userName))
        {
            if (user == null)
            {
                throw new ArgumentException("User not found");
            }

            return user.GetAuthorizationGroups().ToList();
        }
    }
}

using System;
using System.DirectoryServices;
using System.Collections.Generic;

public static List<string> GetUserGroups(string userName)
{
    var groups = new List<string>();
    var de = new DirectoryEntry("LDAP://yourdomain.com");
    var ds = new DirectorySearcher(de);
    ds.Filter = string.Format("(&(objectClass=user)(sAMAccountName={0}))", userName);
    ds.PropertiesToLoad.Add("memberOf");
    var result = ds.FindOne();

    if (result != null)
    {
        var memberOf = result.Properties["memberOf"];

        foreach (string group in memberOf)
        {
            groups.Add(group);
        }
    }

    return groups;
}